x86/platform/uv: Setup UV functions for Hubless UV Systems

Upstream commit 2bcf265

Add more support for UV systems that do not contain a UV Hub (AKA
"hubless").  This update adds support for additional functions required:

    Use PCH NMI handler instead of a UV Hub NMI handler.

    Initialize the UV BIOS callback interface used to support specific
    UV functions.

Signed-off-by: Mike Travis <[email protected]>
Reviewed-by: Steve Wahl <[email protected]>
Reviewed-by: Dimitri Sivanich <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Hedi Berriche <[email protected]>
Cc: Justin Ernst <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Orabug: 30518602
Signed-off-by: Somasundaram Krishnasamy <[email protected]>
Reviewed-by: John Donnelly <[email protected]>

Author: mike-travis

arch/x86/kernel/apic/x2apic_uv_x.c

@@ -1484,6 +1484,20 @@ static void __init build_socket_tables(void)
 	}
 }
 
+/* Initialize UV hubless systems */
+static __init int uv_system_init_hubless(void)
+{
+	int rc;
+
+	/* Setup PCH NMI handler */
+	uv_nmi_setup_hubless();
+
+	/* Init kernel/BIOS interface */
+	rc = uv_bios_init();
+
+	return rc;
+}
+
 static void __init uv_system_init_hub(void)
 {
 	struct uv_hub_info_s hub_info = {0};
@@ -1623,8 +1637,8 @@ static void __init uv_system_init_hub(void)
 }
 
 /*
- * There is a small amount of UV specific code needed to initialize a
- * UV system that does not have a "UV HUB" (referred to as "hubless").
+ * There is a different code path needed to initialize a UV system that does
+ * not have a "UV HUB" (referred to as "hubless").
  */
 void __init uv_system_init(void)
 {
@@ -1634,7 +1648,7 @@ void __init uv_system_init(void)
 	if (is_uv_system())
 		uv_system_init_hub();
 	else
-		uv_nmi_setup_hubless();
+		uv_system_init_hubless();
 }
 
 apic_driver(apic_x2apic_uv_x);